JP2000314991A - Document feeder - Google Patents

Abstract

(57) Abstract: An object of the present invention is, for example, a sheet-through type document feeder, in which the size of a document passing through a processing position while being transported is reliably detected by a small sensor. SOLUTION: A document table 11, a separation roller pair 23,
24, and a pull-out roller pair 25, and the reading position RP
In the document feeder 10 that notifies the size of the document P to be conveyed to the copying machine main body H, the sensor S1 for detecting the set document P, and the document P immediately downstream of the separation roller pairs 23 and 24.
A sensor S2 for detecting the trailing end, a sensor S3 for detecting the leading end of the document P immediately downstream of the pull-out roller pair 25, and a width for detecting the width direction end corresponding to each width in the transport direction of the document P Sensors S4 to S8 are provided, and sensors S2, S
3 are spaced apart from each other so as to have an interval exceeding one half of the length of the maximum size document P in the transport direction,
The size of the document P to be conveyed is determined based on the detection signal of S8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document feeder, and more particularly to a document feeder which can be suitably applied to a device mounted on a device for reading a document image by a sheet through system.

[0002]

2. Description of the Related Art Conventionally, there has been known a document feeder which separates documents set on a document table when a plurality of sheets are stacked, one by one, and transports the documents to a processing position by an apparatus main body. The document is mounted on a scanner, a copying machine, or the like, and transports the set document to a reading position.

As this type of document feeder, for example,
This document feeder employs a sheet-through system in which a document is conveyed and passed to a reading position where an image is read from a document passing over a contact glass. I have.

A document feeder adopting such a sheet-through method needs to detect a document size to be processed before a conveyed document arrives at a reading position and notify the apparatus main body. As in the document feeder described in this publication, the document size is detected by a document length sensor arranged in the document conveyance direction on a document placing portion (document table).

[0005]

However, in such a conventional document feeder, the length of the document can be detected while the document is set on the document table. The advantage is that the document size information can be transmitted (notified) to the main unit at the same time as the document size, but the cost is high because many sensors are required to detect the length of the document in the transport direction. In the case of a sensor of the type, since it is exposed to the outside, erroneous detection due to disturbance light such as a fluorescent lamp may occur.When a sensor is arranged at the rear end side of a document, or when a mechanical sensor such as a filler is used. In such a case, there is a problem that the end of the document may not be detected due to the habit of the document such as "fold" or "curl".

Although it is possible to detect the length of the original in the conveying direction by driving the encoder to follow the original being conveyed, there is also a demand for easier detection of the original size.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a document feeder which can detect the length of a document with a small number of sensors and can easily detect all sizes of the document at low cost and easily.

[0008]

Means for Solving the Problems A first method for solving the above problems is described below.
According to the invention, a document table on which a document is set, transport means for transporting the loaded document to a processing position by the apparatus body, length detecting means for detecting the length of the transported document in the transport direction, and the document to be transported And a width detecting means for detecting a width in the conveying direction of the document feeder. As a detecting means, a document conveying path between the document table and the processing position
A first length sensor for detecting the trailing end of the conveyed document and a second length sensor for detecting the front end of the document are provided, and the first and second length sensors convey the document. The document is characterized in that it is separated so as to have an interval exceeding one half of the length of the maximum size document in the transport direction.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, the length detecting means includes a first detecting means.
A third length sensor is disposed between the length sensor and the second length sensor, and the third length sensor is a distance that is の of the length of the maximum size original to be transported in the transport direction. , And is disposed immediately upstream of a position separated from the first length sensor.

According to a third aspect of the present invention, in addition to the configuration of the first or second aspect, the width detecting means includes a document conveying path between a document table and a processing position.
A plurality of width sensors for detecting the width of the document to be conveyed are provided, and the width sensors are arranged at positions for detecting the side for each different side position from the reference position in the width direction of the document to be conveyed. It is characterized by the following. In addition, this width sensor may be disposed at a position where the first and third length sensors are disposed.

According to a fourth aspect of the present invention, in addition to the configuration of the third aspect, the width sensor is arranged at a position for detecting a leading end of a document set on a document table,
The document size is determined based on a detection signal detected during document setting and document transport.

According to the first aspect of the invention, the length of the document conveyed from the document table to the processing position has the maximum length in the document conveyance direction when the first and second length sensors detect the leading edge and the trailing edge simultaneously. While it is detected that the original is larger than half the size, if the first and second length sensors cannot detect the leading and trailing edges simultaneously, the length of the original in the transport direction is equal to or less than half the maximum size. Is detected, and the size of the document can be determined based on the detection signal from the width sensor in the width detecting means, for example, in the third invention. Therefore, regardless of the encoder or the like, the document is not affected by the "folding" or "curl" of the document and is not affected by the disturbance light in the transport path in the apparatus. The document size can be determined by a simple sensor that only detects the presence or absence of the document.

In the second invention, the original conveyed from the original table to the processing position has a maximum size in the original conveyance direction depending on whether the originals are simultaneously detected by the first and second length sensors. It is detected that the original size exceeds or is less than or equal to の 長, and the length of the original in the transport direction is あ る い は or 1 of the maximum size depending on whether or not the first and third length sensors simultaneously detect the original. / 2 is detected. Therefore, it is possible to detect the length of many originals in the transport direction among the original sizes at an early stage to determine the original size.

In the fourth aspect of the present invention, the width of the document conveyed from the document table to the processing position is detected by the width sensor in the document conveyance direction while being set on the document table. Therefore, the width of many documents among the document sizes can be detected at an early stage to determine the document size.

The present invention can be suitably applied particularly to those employing a sheet-through system in which a document is conveyed and passed through a processing position.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. 1 to 4 show a first embodiment of a document feeder according to the present invention.
It is a figure showing an embodiment.

In FIG. 1, a document feeder (Auto Docum
ent Feeder) 10 is, for example, a standard A3 size original P
Each unit of the apparatus described below is designed so that the document P which can be processed in the portrait orientation is the largest, and is mounted on the image reading apparatus 100 of the copying machine main body H.
Is a separation unit 12 for separating and feeding the documents P stacked on a document table 11 one by one, and an image reading device for separating the separated and fed documents P between a contact glass 101 and a white guide plate 104. And a transport unit 13 that transports the paper 100 to a reading position (processing position) RP and carries it out to the discharge table 14. That is, the separation unit 12 and the transport unit 13 constitute a transport unit. The image reading apparatus 100 deflects, by a mirror 103, irradiation light (reflected light) of an exposure lamp 102 reflected by an image surface of a document P passing over a contact glass 101, and a CCD (not shown).
Then, the image of the document P is read.

The original P is set on the original table 11 with the image surface facing upward and the end abutting against the stopper 21, and the end of the original P is detected by a sensor S 1 described later.

In the separating section 12, when a start button provided on the apparatus main body (not shown) is pressed while the sensor S1 detects the set document P on the document table 11,
The stopper 21 descends (retreats) to the position indicated by the broken line in FIG. 1 and the call roller 22 moves down to the position indicated by the broken line in FIG. , 24 to the nip. The separation roller pair 23, 24 is configured to rotate the feeding roller 23 clockwise while the return roller 24 rotates counterclockwise, thereby restricting the lower side of the document P from being fed. Are separated and fed one by one downstream.

In the transport section 13, the pull-out roller pair 25 of the driving roller and the driven roller sandwiches the separated original P and transports it to the reading position RP of the copying machine main body H. The paper discharge roller pair 26 of the driving roller and the driven roller is nipped and carried out onto the paper discharge table 14.

The document feeder 10 includes a document table 1
The sensors S1 to S3 for detecting the original P are provided in the middle of the transport path between the first and the reading positions RP, and as shown in FIG. Side fence fixed to (not shown)
Sensors S4 to S8 that detect based on
The sensors S1 to S8 notify the copier main body H of information obtained from a detection signal obtained by an optical (for example, presence or absence of reflected or transmitted light) detection method.

The sensor S1 is disposed on the leading end side of the document table 11, and the document feeder 10 detects the leading edge of the set document P from the detection signal of the sensor S1 and the setting state of the document P together with the setting state of the document P. The presence or absence is determined (detected) and notified to the copying machine main body H.

The sensor S2 is disposed immediately downstream of the pair of separation rollers 23 and 24, and detects the rear end of the separated and fed original P. The sensor S3 is located immediately downstream of the pair of pullout rollers 25. The sensors S2 and S3 detect the leading end of the placed and transported original P, and the sensors S2 and S3 are arranged at intervals exceeding one half of the length of the maximum size (A3 length) original P to be transported in the transport direction. It is arranged in a position to be separated. Therefore, the document feeder 10 determines whether or not the sensor S2 detects the trailing edge of the document P based on when the sensor S3 detects the leading edge of the document P (the detection of the trailing edge of the document P by the sensor S2). At this time, it may be determined whether or not the sensor S3 detects the leading edge of the original P). As shown in FIG. 2, the length of the original P in the transport direction of the original P exceeds 1/2 the A3 length.
(Excluding A5) can be determined (detected). That is, the sensors S2 and S3 constitute the length detecting means of the first length sensor and the second length sensor.

The sensors S4 to S8 are arranged at positions adjacent to the sensor 1 in the direction of transport of the document P (in FIG. 1, the sensor S2 is shown adjacent to the sensor S2 for convenience). (Side fence side) The sensor S5 is disposed at a position corresponding to the end, and the sensor S5 is located on the outer side of the side of the front side of the A5 length B
The sensor S6 is disposed at a position corresponding to the end of the A5 horizontal (A4 length) on the outer side of the front side of the B5 vertical, and the sensor S7 is disposed at a position corresponding to the end of the A5 horizontal ( The sensor S8 is disposed at a position corresponding to the end of the B5 landscape (B4 length) outside the side of the front side of the A4 length).
A4 horizontal (A) outside the side on the front side of 5 horizontal (B4 vertical)
(Vertical 3). Accordingly, the document feeder 10 detects (ON) the document P on which the sensor S4 is set, and at the same time, the sensors S5 to S5.
Based on the ON / OFF detection of S8, as shown in FIG. 3, the document P is narrowed down to any one of A5 length to A3 length, and A is detected only by the detection signals of the sensors S4 to S8.
It is possible to determine the case where the 5-size document P is placed vertically and the case where the B5-size document P is placed vertically, and it is possible to determine whether the width of the document P in the transport direction is the same. it can. That is, the sensors S4 to S8 constitute a width detecting unit of the width sensor.

From this, the document feeder 10 sets the sensor S2 based on when the sensor S3 detects the leading end of the document P.
4, the width of the document P is the same based on whether or not the rear end of the document P has been detected, and which of the sensors S4 to S8 has been detected on the document table 11 as shown in FIG. For example, it is possible to determine whether the original P is A3 portrait or A4 landscape, and notify the copier main body H of the fixed size of the original P and whether the original P is placed vertically or horizontally. Has become. Note that the original P placed in the A5 size portrait or B5 size portrait orientation can be determined only by the detection signals of the sensors S4 to S8 which can be detected when the original P is set. Immediately after the button is pressed, the copying machine main body H can be notified.

At this time, the document P is inserted under the call roller 22 (may be held down by the call roller 22 or the pair of separation rollers 23, 24), or is inserted into the pair of separation rollers 23, 24 or the pull-out roller 25. The sensor S1
Since the document P is detected in S8, the document P
Even if there is a habit such as "L", it can be reliably detected, and it can be detected by a simple position sensor such as the sensors S1 to S8 that simply detects the presence or absence of the document P at the installation position. The sensors S1, S4 to S8
Are accommodated in the cover 15 together with the call rollers 22 and the like, so that they are not affected by disturbance light that may cause erroneous detection. In addition, since the sensor S1 detects the setting and presence or absence of the document P, it goes without saying that a mechanical sensor that detects a filler or the like rotated by the document P may be installed.

As described above, in this embodiment, erroneous detection due to the habit of the document P or disturbance light occurs only by disposing the sensors S2 and S3 in the middle of the transport path from the document table 11 to the reading position RP. The length detecting means can be configured without any length. The simple position sensors S1 to S8 determine the size of the document P from A5 to A3 and whether it is placed vertically or horizontally and notify the copying machine main body H. be able to.

As another aspect of the present embodiment, although not shown, the sensors S4 to S8 may be arranged in the middle of the conveyance path of the document P. For example, the sensors S4 to S8 may be installed adjacent to the sensor S2 or S3. Can function similarly. In this case, since the sensors S4 to S8 are housed inside the downstream side of the cover 15, the influence of disturbance light can be further reduced. Needless to say, the sensor S4 may be used also as the sensors S1, S2, and S3. Further, when a registration sensor for detecting the leading edge of the document P is used in order to take the timing to convey the document P to the reading position RP, it goes without saying that the sensor 3 may also be used.

FIGS. 5 to 7 show a second embodiment of the document feeder according to the present invention. In addition, since the present embodiment is configured substantially in the same manner as the above-described embodiment, the same components are denoted by the same reference numerals, and the description will be focused on the characteristic portions.

In FIG. 5, the document feeder 10 includes a pair of separation rollers 23 and 24 and a pair of pull-out rollers 2
5, a conveying roller pair 31 of a driving roller and a driven roller is disposed, and a conveying roller pair 32 is disposed between the reading position RP and the paper discharging roller pair 26. A short distance (interval) that is half the length of the maximum size (A3 length) original P to be transported in the transport direction immediately after the downstream side of the transport roller pair 31 is transported in a nipping manner. At a position immediately upstream of the position separated from the sensor S2 by
A sensor S11 for detecting the conveyed document P by an optical system is provided, and information obtained including a detection signal of the sensor S11 is notified to the copying machine main body H side.
That is, the sensor S11 forms a third length sensor.

Therefore, the document feeder 10 uses the sensor S11 as a reference when the sensor S11 detects the leading end of the document P.
2 when the sensor S11 detects the trailing edge of the document P (the sensor S11 detects the trailing edge of the document P when the sensor S2 detects the trailing edge of the document P).
Whether or not to detect the tip), as shown in FIG. 6,
It is possible to determine (detect) whether or not the document P is a landscape document P (excluding A4) in which the length of the document P in the transport direction is less than 1/2 of the A3 length.

Accordingly, the document feeder 10 determines whether or not the sensor S2 detects the trailing edge of the document P based on the time when the sensor S11 detects the leading edge of the document P. Based on which of the sensors S4 to S8 has detected on the table 11, as shown in FIG. 7, the size of the document P other than the A3 length and A4 width documents having the same width in the transport direction of the document P is determined. After that, as in the above-described embodiment, the sensor S
3 detects the leading edge of the document P, the A3 length and A4
The size of the document P, including the width, can be determined, and the copier main body H is notified of the fixed size of the document P determined at each detection timing and whether the document P is placed vertically or horizontally. It has become.

As described above, in this embodiment, in addition to the functions and effects of the above-described embodiment, the possible size of the original P can be sequentially determined at an early stage, and the size of the original P can be efficiently processed. To the copying machine main body H.

[0034]

According to the present invention, the length of a document transported from the document table to the processing position in the transport direction is one of the maximum size.
/ 2 is detected during the conveyance of the document, and the size of the document is determined based on the detection information of the width in the conveyance direction of the document. Therefore, erroneous detection due to the habit of the document or disturbance light occurs. Without discarding, the entire size of the original can be determined by a simple sensor that is simply arranged on the transport path from the original table to the processing position. Therefore, it is possible to easily and inexpensively determine all the document sizes with a small number of sensors and notify the apparatus body.

Also, 1/2 or 1/2 of the maximum size
Adding one sensor to detect if it is less than
By detecting the width of the original in the transport direction when the original is set on the original table, many original sizes can be identified at an early stage, and the original size can be notified to the apparatus body so that the original can be processed efficiently. Can be.

[Brief description of the drawings]

FIG. 1 is a schematic overall configuration diagram showing a first embodiment of a document feeder according to the present invention.

FIG. 2 is an explanatory diagram showing a positional relationship between a document size and a sensor.

FIG. 3 is a table showing the detection results.

FIG. 4 is a table showing detection results at timings different from those in FIG. 3;

FIG. 5 is a schematic overall configuration diagram showing a second embodiment of a document feeder according to the present invention.

FIG. 6 is an explanatory diagram showing a positional relationship between the document size and a sensor.

FIG. 7 is a table showing the detection results.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Document feeder 11 Document table 12 Separation part (conveying means) 13 Conveying part (conveying means) 15 Cover 22 Calling roller 23 Feeding roller 24 Return roller 25 Pullout roller pair 26 Paper discharge roller pair 31, 32 Transport roller pair 100 Image Reading device 101 Contact glass H Copy machine main body P Document RP Reading position S1 sensor S2 sensor (first length sensor) S3 sensor (second length sensor) S4 to S8 sensor (width sensor) S11 sensor (third length sensor) )

Claims (4)

[Claims] An original table on which an original is set; conveying means for conveying the set original to a processing position of the apparatus main body; length detecting means for detecting the length of the original to be conveyed in the conveying direction; And a width detecting means for detecting a width of the document in the conveying direction, wherein the document feeding device determines a size of the document to be conveyed based on the length detection information and the width detection information and notifies the apparatus main body, A first length sensor for detecting the trailing edge of the conveyed document and a second length sensor for detecting the leading edge of the document are provided on the document conveying path between the document table and the processing position. The first length sensor and the second length sensor are separated from each other so as to have an interval exceeding one half of the length of the maximum size document to be conveyed in the conveyance direction. apparatus. 2. A length sensor, wherein a third length sensor is provided between a first length sensor and a second length sensor, and the third length sensor has a maximum size to be conveyed. 2. The document feeder according to claim 1, wherein the document feeder is disposed immediately upstream of a position separated from the first length sensor by a distance that is の of a length of the document in the conveyance direction. 3. 3. A plurality of width sensors for detecting the width of a conveyed document are provided on the document conveyance path between a document table and a processing position as the width detection means, and the width sensor conveys the document. 3. The document feeder according to claim 1, wherein the document is arranged at a position where the side is detected for each different side position from the reference position in the width direction of the document. 4. A method according to claim 1, wherein said width sensor is arranged at a position for detecting a leading edge of a document set on a document table, and discriminates a document size based on a detection signal detected during document setting and document conveyance. The document feeder according to claim 3, wherein: